Apparatus for electric ignition.



G. HONOLD.

APPARATUS FOR ELECTRIC IGNITION.

APPLICATION FILED MAR. 29, 1911.

Patented J an. 27, 1914 2 SHEETS-SHEET l.

MECHANICAL INTEFUPTE'I? wL/aplm F M wh czx/ G. HONOLD.

APPARATUS FOR ELECTRIC IGNITION.

APPLICATION FILED MAR. 29, 1911.

Pat :bed Jan. 27, 1914.

2 SHEETS-SHEET 2.

ITIJESSES UNITED sTATE-s PATENT OFFICE.

Go'r'rLoB HON'OLD, or STUTTGART, GERMANY, Assieivon TO THE new: orROBERT BOSCH, or s'rn'r-rsnncr. GERMANY.

APPARATUS FOR ELECTRIC IGNITION.

Specification of Letters Patent.

Pitt outed Jan. 27, 1914.

le -(whoa it) myinveijitkm in order to ol vine: lhe necessity ofIi'ltiiilllg the spark.

and useful Improvements in Apparatus for i Electric Ignition; and I dohereby-declare the following to be a full, clear, and exact descriptionof the invention, such as will on able others skilled in the art towhich it appertains to make and use the same.

The present invention relates to a paratus for electric ignition of thecombustible gases in a single or multiplecylinder internal combastionengine.

As is well understood by those conversant with the art, the fulldevelopment of pressure produced in the cylinders of engines of thiskind by the explosion of the fuel should always take place immediatelyafter the crank has passed the dead point at the head ehd of the stroke.New under ordinary conditions the time which elapscs between themomentin which the ignitin spark is generated and the moment in wiich theexploding combustible 'niixture develops the-maximum pressure, is

more or less constant, and it follows that, if the maximum pressure isto be developed in a certain phase of the stroke, the moment of ignitionor of generatin the spark must be advanced when the speed of the engineis increased. Hitherto therefore in engines of this kind means haveinvariably been provided for shifting the apparatus controlling themoment of lgnition, that is to say the interrupter of the primarycurrent. ,This method of mechanically adjusting the igniting apparatusinvolves the necessity of making this apparatus accessible to the op.-erator either directly or by providing "transmitting means such as rods,levers, chains and such like.

It is the object of my invention to obviate the use of such mechanicaltransmitting members and substituting therefor electric means which aremuch more easily adapted to all such dispositions of mac inery inwhich'the operator controlling the engine cannot be given direct accessto all parts of the machinery under his control during ing point or thepoint of interruption of the prm'ciry current ad ustable, I propose totake advantage of the fact that the time consumed between the moment ofignition and the moment in which the full pressure .of the explosion isdeveloped, canbe made to vary considerably by varying the number ofsparks employed to ignite the explosion mixture. I have found byexperiment that, if, instead of, employing only one spark to ignite theexplosive mixture in the cylinder, I employ a plurality of simultaneoussparks, the time consumed by the process of explosionor in other wordsthe time elapsing between the moment of ignition and the moment in whichthe maximum p essure is develo ed is considerably reduced. Moreover havefound that as the number of simultaneous igniting sparks is increasedthe time absorbed by the sion does not only diminis in inverse pro--portion to the number of sparks, but according to a higher er. Theexactlaw by which the diminution of the time of explosion is governed is notreadily capable of a geneml expression, because.it is subject to greatvariations depending upon the size and dimensions of the cylinder, thedegree of compression and other similar conditions, that may varyconsiderably. In any case however the increase of speed of combustionwith duplicate sparking plugs only is so great that I find it possible,even for -the highest practical speeds of the engine crank, to fix themoment of ignition so as to make it coincide with the dead point of thecrank at the head end of the stroke or only very slightly in advance ofthe dead point. If then, by means hereinafter'more fully described, oneof the pair of sparking plugs is made inoperative, the enginewillprocess of explothus be adapted tobe run at slow speeds or to he started'without the risk of sudden reverses occurring. Y

My invention therefore consists in proyiding an internal combustionengine with a plurality of sparking plugs-for every cylinder and insteadof4employingthe usual mechanical means for shifting the moment ofignition or of interruption of the primary igniting current according tothe speed of the engine, I provide means for switching 1 the manner inwhich the .tially the samein all on or of! fine or more sparking plugsin every cylinder accordingly as the engine is to be adapted'to higheror lower s eeds.

In practice and more especiaii smaller size of engines I find itsufiicient to provide two sets of sparking plugs connected to thegenerating plant in such a manner that both plugs of each cylinder willgenerate their sparks simultaneously. In the accompanying drawingstherefore I haveillnstrated an embodimentof my invention in which thenumber of sets of smrking plugs is thus limited, because comprehensionof the nature of my invention is thus rendered more easy. But I wish itto be understood that I do not "limit myself to double sets of plugs. Inunusually large engines or in cases in which unusual variations of eedare required, it may become necessary .or desirable to use a largernumber of sets of plugs; But are to be employed according to-myinvention will be substancases and any expert will be readily ableaccording to rules well known and understood in the art to so mot lityand multiply the connections shown in the drawing as to adapt thearrangement to the use of multiple sets of sparking plugs.

In the accompanying drawings Figure 1 is a diagrammatical illustrationof the means employed for reducing my invention to practice by means ofa magneto igniter and of the manner in which such means are to beconnected in order to act according to my invention. Fig. 2 is a.diagrammatical illustration of a modification of the means shown in Fig.1 and Fig. 3 is a diagrammatic illustration of. a modification of theconnections shown in Figs; 1 and2, as employed in case in which theigniting sparks are to be generated by means of a battery instead of amagneto.

Corresponding parts are designated by the' same reference characters inall the drawings.

Referring to Fig.1 0 represents the head end of a cylinder of aninternal combustion engine the inner end being drawn broken away and Ithe piston thereof.

K, and K are a pair of sparking plugs ofv usual construction having oneelectrode connected, to a clamping screw at the head of the plug and theother electrode connected to the mass of the cylinder or to ground.

A is a magneto-generator of usual construction supposed to be drivenbythe engine or in any other suitable and usual manner.

S, and S, are a. pair of sliprings prefen ably mounted on the armatureshaft of the magneto and rotating therewith and being connected to theterminals ol the seoomlary armature winding by means of insulated wiresI and E I5, and 15 are a pair of brushes adapted to slide on saidsliprings S, and S, and connected\ by leads L and L to the clampingscrews of the sparking plugs K and K D is the contact lever of a switchconnected by'a. lead L, to the mass of the cylinder and being capable ofmaking connection alternately with-contacts D and D connected by leadsL, and L to points. on leads L and L intermediate the brushes B and Band the plugs K and The primary winding P, of the magneto armatureincludes a mechanical interrupter, which is operated according to ruleswell known in the art either from the armature. shaft or any othersuitable moving part of the engine so as periodically to short circuitand to, interrupt the primary winding and according to mypresentinvention thisLinterrupter may have a fixed adjustment, so as tocause an interruption every time the piston arrives at the dead point ofthe stroke or very shortly before that point. Likewise it will beunderstood that, in order. to accommodate a plurality of cylindersinstead of a single one, as shown in the drawing, a distribute!" which,-according to methods well understood, may be placed either in thecircuit of the primary or.that of the secondary current. The arrangementthus illustrated operates as follows: Every time a current impulse is 9generated by the armature of the magneto itis transmitted through theslipr'ings S, and 5 the brushes B and It, the leads L and L to the plugsK and K \Vhen the switch I) is in the central position, as shown in thedrawing, both plugs are connected in series and simultaneous sparksaregenerated in both, thus adapting the engine to high \V hen low speedsare required or speeds.

when the engine has been at rest and it is intended to start it, theswitch lever D is turned to make contact either with D or 1),. Inthetirst. instance the plug D and in the second instance .the plug D isshort circuited and the current impulse generates a single spark in theremaining plug. The time elapsing between the moment of ignition and thedevelopment of the full pressure of the explosive is thus increased andthe la thus obtaincdis SutIr llg h cicnt to obviate reverses of theengine in starting and to produce a good output, when the engine is keptat low speeds for a longer period of time.

In Fig. 2 a modification of this arrangement is shown which differs fromthat illustrated in Fig. 1 only in the arrangement of the/brushes andsliprings, these parts being disposed in such a manner as to obviate thenecessity of placing both sliprings in vdit' ierent planes, thusdiminishing the length of armature shaft required to aeconnnoilalethesliprings. Instead of providing twoseparate sliprings, in this case Idivide one slipiing into two segments S, and 3 arranged at the head end85 will have to be added ga;

therefore 1 l0 neonate in the same plane and connect the terminals ofthe secondary iii-mature. winding A with these egments exactly in thesame manner as described with reference to the separate sliprings inFig. 1. This arrangement has the etl'ertv that the direction of everysecond mirrenr impulse passing through the plugs is reversed. But, sincethe direction of the current whichis employed for generating an ignitingspark is of no importance, this (iitlerenee does notQpro-ducc any changein the operation of the arrangement.

Fig. 3 illustrates the eonni-xctions used for embodying my invention insuch cases in which a battery is preferred for generating the sparkingcurrent. One terminal of a battery B is grounded at B and is thus inconnection with the mass of an interrupter I, the latter connettionbeing made separable by means of a SWlkCli at that drawn opened but issupposed to be closed during operation. ()n a. lever l tulcrumed at 2 onthe frame of the interrupter is disposed a movable contact pin 3 and ona block 4 secured to the frame of the interrupter but insulatedtherefrom is disposed another contactpin 5. A spring ti seouretjl at oreend to a block fastened on or integral with the frame 'ilate of theinterrupter and secured at the other end to the tail end t lever 2 tendsto retain the pins 3 and in (mutant with each other. Block -11 isconnected to one terminal of a primary winding G, an induction coil Gthe other terminal. being connected to the second terminal of the batterThe frame plate of the int iter is supposed tmbe mounted on a. rotatingpart of the en ine soas to take part. in the rotation in accordunoe withthe well understood practice of the. art and a cum 8 deflects the tailend at lever 1 at determined periods and thereby separatrs th mintsctpins and in terrupts the circuit.

Coil. G is provided with a secondary wind mg (i, one terminal of whichconnected to the rotating contact. or brush of a distribu to F, and theother with the corresponding brush of a distribute! F Four cylinders C CC and (here shown, the head plates only being drawn and each cylinder ispro rided with two sparking plugs, cylinder C having the plugs K, andvii the cylinder (.3, the plugs lib" and IQ" and so forth filtl theinwulaied electrodes (5 w 'gi ug-= are connected in thrspective ordc,.-.illi tioinir contacts v f, 1", ."th of dietributers F, and F The termill;- of the sec {iii f and I' l.

v winding t} are bridgiui by a switch D with contacts i and D arrangedas ii the modifications described ith n-lrreiiri'e to Fig nd Thel'll:ll'.S of 1 u em? to roiipl-ri in such a ins-inne that httt't'lll'l't llll t lz ljl .rl lgfr with the srco'ntlurv whirling t w r lithi'flil for ,develop full When the switch lever D is moved into,

contact either with D or D either the set. of sparking plugs indexed 1or the set indexed 2 is shorteircuited and the other set only remains inoperation thereby increasing the time elapsing between the moment ofinterruption and the moment in which the maximum pressure is developedby the explosive and enabling the engine to ower at low speeds or makingit capable 0 being started without danger of reverses.

It stands to reason that the action of the arrangement illustrated inFig. 3 would be substantially the same if for the battery amagnetogenerator was substituted for generating the sparking current andalso that a number of other modifications of the connections hereinillustrated by way of example might be elaborated for producing the sameeffect. But I wish it to be understood that my invention is notconcerned with these details which are all well knownand understood, butthat it refers only to the described method of and means for varying thetime consumed in the process of ex plosion for the purpose of obviatinthe use of means for shifting the moment 0 i ition or the moment ofinterruption of t e primaly current.

Vvhat I claim is: w

1. In an electric ignition system for an internal combustion engine, a.lurality of spark plugs in a cylinder of e engine, a source of sparkingvoltage including a single secondary winding, means for generating insaid secondary Winding at all speeds of the engine a sparking voltage infix d time relation to the successive periods oi maximum compression inthe cylinder, tilzfillltflil" connections for coi'inecting the serondarywinding to all the spark plugs to produce sparks simultaneously thereat,and a switch and connexrtions for rendering permanently inoperative oneof said spark p ngs at will without rendering other or u is of the sparkplugs inoperative.

J in an electric ignition system for an incombustion engine, two sparkplugs in a cylinder of the engine, a source of :parking voltageincluding a single secondary winding, means for generating in said goosecondary winding at all speeds of the engine a sparking voltage infixed time relation to the successive periods of maximum compressiOn inthe cylinder, electrical connections for connecting the secondary Wind-'ing to all the spark plugs to produce sparks simultaneously thereat, amulti-point switch and CullllOCtlGIlS for rendering both spark plugsoperative, for short-circuiting at will one of the spark plugs to renderit permanently inoperative, and for short-circuit ing at will the otherof the spark plugs to render it permanently inoperative.

3. In an electric ignition system for a multiple cylinder internalcombustion engine, a plurality ofspark plugs in each cylinder, amagneto-generator having a primary and a secondary circuit, means felrperiodically short-cireuiting and interrupting the primary circuit togererate at all speeds at sparking potential in fixed time relation tothe successive periods of maximum compression in the several cylinders,electrical connections including a distributer for successivelyconnecting the generator with the spark plugs in the several cylindersto produce sparks thereat substantially at the time when the maximumpressure exists plugs,

in each cylinder, and a switch and connections for rendering inoperativeone or more spark plugs in each of the several cylinders.

4. In an electric ignition system for an internal combustion engine, twospark plugs in the cylinder of the engine, a magnetogenerator havingprimary and secondary windings and a slip ring comprising two insulatedsegments electrically connected to the terminals of the secondarywinding, means for periodically closing and interrupting the circuit ofthe primarv winding in fixed time relation to the period of maximumcompression in the engine cylinder, a

pair of diametrically disposed brushes adapted to contact with the slipring, electrical connections for connecting the brushes with theinsulated edectrodes of the spark and a switch and connections forrendering inoperative one of the two spark plugs. i

In testimony whereof I' have affixed my signature, in presence of twowitnesses.

G OTTLOB HONOLD.

Vitnesses MAX Ansontirz, REIN HOLD ELWERT.

